If you’re wondering just what the hell happened to your money — why you’re working more for less, for example, while the head of your company is taking home millions — you might want to listen to Robert Reich.

He’s a former Washington insider (secretary of labour under Bill Clinton, although he also worked for Bush), now an author and a professor at Berkeley, and his theories about the pummelling of the middle class and the rise of the one per cent are lucidly laid out in Inequality For All, a documentary about the economy.

Documentaries about the economy being what they are, you might not expect much from Inequality For All, but as directed by Jacob Kornbluth, it is the Indianapolis 500 of wealth analyses. The diminutive Reich (he suffers from Fairbanks disease and arrives at lectures with his own box so he can reach the podium) is an engaging, intelligent and persuasive analyst, and the film — essentially a long illustrated lecture — is easy to follow.

Much of it sounds like a left-wing position, but Reich makes the case that he has just been sitting in the middle of the argument watching the playing field migrate to the right.

The film argues that the United States (and by extension Canada) has become a less equal society because it is suppressing its middle class, who are the true makers of wealth and creators of jobs.

His charts show how the era of the least equality — that is, when the disparity between the richest and the poorest was the greatest — came in 1928 and 2007, both times just before famous crashes.

Former U.S. labour secretary Robert Reich, left, and director Jacob Kornbluth discuss the U.S. income gap

In 2007 for instance, the top one per cent of Americans held 23 per cent of all the wealth.

Reich talks to a few of them, including investment guru Warren Buffett (total worth: $86 billion) who says he paid income tax at a rate of 17.7 per cent.

Under Eisenhower, who was certainly no socialist, the marginal tax rate in the U.S. was 91 per cent.

Buffett thinks it’s unfair.

On the other side of the coin is Philippe Dauman, the head of Viacom (annual salary: $84 million), explaining in a TV clip why the company had to lay off workers to stay competitive.

Reich also talks to a few working-class families who barely scrape by on two incomes: one couple has $80 in their chequing account.

Reich explains where the money goes when you buy, say, an iPhone (most to Japan; only six per cent to the U.S.).

He’s a big supporter of unions and an educated workforce, and the clips of union-busting companies and charts of rising tuition fees are part of a one-sided but illuminating argument. Inequality For All makes no attempt at balance: The other side is represented by clips from The Daily Show of right-wing politicians being mocked by Jon Stewart.

But maybe the other side is already making its case, in our day-to-day lives. Reich shows how average salaries have remained steady, or even dropped, since the late 1970s while the top salaries have risen to the billions.

Nor is there much trickle-down benefit. A Seattle entrepreneur named Nick Hanauer, who makes more than $10 million a year, says his money doesn’t get spread around much: He has just one Audi and there are only so many nights in a year when he can go out to eat.

Hanauer’s company makes pillows, and he says that even rich people only sleep on one or two of them. The super wealthy don’t churn the economy the way a healthy middle-class can.

Inequality For All comes up short when it looks for solutions: It ends with Reich’s last class as he delivers an idealistic speech about hope. It’s not much to hang on to, but it seems to be all that is left.